[squid-users] No failover when default parent proxy fails (Squid 3.5.12)

[Amos Jeffries]

On 15/03/2017 7:06 p.m., Jens Offenbach wrote:
> Hi,
> I have two parent proxies configured, but Squid seems to stick to the default proxy even when the proxy cannot be reached:
> 2017/03/15 06:40:13 kid1| TCP connection to proxy.mycompany.de/8080 failed
> 2017/03/15 06:40:13 kid1| Detected DEAD Parent: proxy.mycompany.de
> 2017/03/15 06:40:13 kid1| TCP connection to proxy.mycompany.de/8080 failed
> 2017/03/15 06:40:13 kid1| TCP connection to proxy.mycompany.de/8080 failed
> 2017/03/15 06:40:13 kid1| TCP connection to proxy.mycompany.de/8080 failed
> 2017/03/15 06:40:13 kid1| TCP connection to proxy.mycompany.de/8080 failed
> 2017/03/15 06:40:13 kid1| TCP connection to proxy.mycompany.de/8080 failed
> 2017/03/15 06:40:13 kid1| TCP connection to proxy.mycompany.de/8080 failed
> 2017/03/15 06:40:43 kid1| TCP connection to proxy.mycompany.de/8080 failed
> 2017/03/15 06:40:43 kid1| TCP connection to proxy.mycompany.de/8080 failed
> 2017/03/15 06:40:43 kid1| TCP connection to proxy.mycompany.de/8080 failed
> 2017/03/15 06:40:43 kid1| TCP connection to proxy.mycompany.de/8080 failed
> 2017/03/15 06:40:43 kid1| TCP connection to proxy.mycompany.de/8080 failed
> 2017/03/15 06:40:43 kid1| TCP connection to proxy.mycompany.de/8080 failed
> 2017/03/15 06:40:43 kid1| TCP connection to proxy.mycompany.de/8080 failed


Appearances can be deceiving at times. This shows that several "a
connections were attempted but does not specify if that was the orider
they were initiated or not.
 It also does not indicate whether that was HTTP or probe for
ressurected peer.

You have disabled the probes though (no-query no-digest) so it is
unlikely Squid will ever detect a DEAD peer as coming alive again. This
makes me suspect that the "roxy" peer was also detected dead some time
earlier. If that has happened then the "FIRST_AVAILABLE" peer selection
algorithm will produce no possible routes and Squid falls back to the
DEFAULT peer ... which happens to be that one you see in the log and
will try that peer until it works again.

If you want to see the exact route selection results add this to your
squid.conf:
 debug_options 44,2


Amos